Controller for vehicle

Abstract

A control apparatus for a vehicle includes a power transmitting system between an engine and wheels. The transmitting system has a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode and an assisting operation mode. The motor-generator serves as a generator in a regenerating operation mode and as a motor in an assisting operation mode. The apparatus includes an electric control unit (ECU) that determines a shift of engine speed, computes the total amount of torque of the engine, the CVT and the motor-generator and selects one of the operation modes and actuates the motor-generator base on the selected operation mode to corrects the engine speed.

What is claimed: 
     
       1. A control apparatus for a vehicle including a power transmitting system between an engine and wheels, said transmitting system having a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode and an assisting operation mode, wherein said motor-generator serves as a generator in the regenerating operation mode and as a motor in the assisting operation mode, said apparatus comprising: determining means for determining a shift of engine speed;   computing means for computing a total moment of inertia of the engine, the CVT and the motor-generator, for computing the torque of the engine, the CVT and the motor-generator based on each of the computed inertia moments and a difference between the engine speeds of the current cycle and the previous cycle, and for computing the total amount of torque; and   correcting means for correcting the engine speed using at least one of said computed values, said correcting means selecting one of the operation modes of the motor-generator to actuate the motor-generator based on the determined shift of engine speed.   
     
     
       2. The apparatus as set forth in claim 1, further comprising: detecting means for detecting a size of a throttle opening, wherein said determining means determines the engine speed shift by comparing the throttle opening of a current cycle to the throttle opening of a previous cycle to determine an increase of the engine speed based on the throttle opening in the current cycle being greater than the throttle opening in the previous cycle, and a reduction of the engine speed based on the throttle opening in the current cycle being smaller than the throttle opening in the previous cycle.   
     
     
       3. The apparatus as set forth in claim 2, further comprising: a memory for storing respective inertia moments of the engine, the CVT and the motor-generator.   
     
     
       4. The apparatus as set forth in claim 3, wherein said determining means compares a target rotational speed of the CVT to an actual rotational speed of the CVT to determine a completion of the increase of the engine speed based on the target rotational speed being greater than the actual rotational speed by at least a first predetermined value and a completion of the reduction of the engine speed based on the target rotational speed being smaller than the actual rotational speed by at least a second predetermined value, and wherein said determining means nullifies the control operation of the motor-generator upon the determination. 
     
     
       5. The apparatus as set forth in claim 4 further including an electric control unit serving as said determining means, said computing means and said correcting means. 
     
     
       6. A control apparatus for a vehicle including a power transmitting system between an engine and wheels, said transmitting system having a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode and an assisting operation mode, wherein said motor-generator serves as a generator in the regenerating operation mode and as a motor in the assisting operation mode, said apparatus comprising: a power source for supplying an electric power to the motor-generator actuated in the assist operation mode and charged by the motor-generator actuated in the regenerating operation mode, wherein said motor-generator regenerates a maximum amount of voltage based on a currently residual voltage of the power source;   computing means for computing a total amount of torque of the engine, the CVT and the motor-generator, and a maximum shiftable speed based on the total amount of the torques and the maximum amount of the voltage;   adjusting means for adjusting a rotational speed of the CVT using at least one of the computed values; and   control means for controlling the adjusting means based on the maximum electric power and a target rotational speed of the CVT.   
     
     
       7. The apparatus as set forth in claim 6, wherein said control means includes: a memory for storing respective inertia moments of the engine, the CVT and the motor-generator; and     regulating means for regulating a current target rotational speed of the CVT so that the current target rotational speed is smaller than the maximum shiftable speed of the CVT.   
     
     
       8. The apparatus as set forth in claim 7, wherein said regulating means includes converting means for forcibly equalizing the current target rotational speed to the maximum shiftable speed of the CVT when the current target rotational speed is greater than the maximum shiftable speed of the CVT. 
     
     
       9. The apparatus as set forth in claim 8, wherein said regulating means includes comparing means for comparing a differential value of the current target rotational speed with the maximum shiftable speed of the CVT. 
     
     
       10. The apparatus as set forth in claim 9, wherein said CVT includes: an input shaft capable of receiving the engine power;   a pair of input plates relatively movable away from and toward each other on the input shaft;   an output shaft:   a pair of output plates relatively movable away from and toward each other on the output shaft;   a power transmitting belt for operably connecting the input plates and the output plates; and   said CVT selectively increasing and reducing a rotational speed thereof based on the relative movement of the input plates toward and away form each other.   
     
     
       11. The apparatus as set forth in claim 10, wherein the adjusting means includes: a hydraulic cylinder for moving one of the input plates based on hydraulic pressure therein; and   an electromagnetic valve for controlling the hydraulic pressure in the hydraulic cylinder.   
     
     
       12. The apparatus as set forth in claim 11, said control means includes an electric control unit for outputting an electric signal to the electromagnetic valve. 
     
     
       13. A control apparatus for a vehicle including a power transmitting system between an engine and wheels, said transmitting system having a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode and an assisting operation mode, wherein said motor-generator serves as a generator in the regenerating operation mode and as a motor in the assisting operation mode, wherein the motor-generated actuated in the regenerating operation mode charges a power source to induce torque required for reducing the engine speed, wherein a maximum chargeable voltage is determined based on a currently residual voltage in the power source, and wherein speed of the vehicle is manually shifted, said apparatus comprising: detecting means for detecting the manual shift operation for reducing a speed of the vehicle;   computing means for computing a total moment of inertial of the engine, the CVT and the motor-generator, for computing the torque of the engine, the CVT and the motor-generator based on each of the computed inertia moments and a difference between the engine speeds of the current cycle and the previous cycle, and for computing the required torque based on the vehicle speed and an acceleration of the vehicle;   comparing means for comparing the required torque and the maximum chargeable voltage; and   control means for controlling the motor-generator, wherein said control means actuates the motor-generator in the regenerating operation mode based on the required torque being smaller than the maximum chargeable voltage, and wherein said control means controls to reduce the rotational speed of the CVT based on an excessive level of the required torque when the required torque is greater than the maximum chargeable voltage.   
     
     
       14. The apparatus as set forth in claim 13, wherein said maximum chargeable voltage is computed based on a maximum capacitance and accumulated voltage of the power source. 
     
     
       15. The apparatus as set forth in claim 14, wherein said CVT includes: an input shaft capable of receiving the engine power;   a pair of input plates relatively movable away from and toward each other on the input shaft;   an output shaft:   a pair of output plates relatively movable away from and toward each other on the output shaft;   a power transmitting belt for operably connecting the input plates and the output plates; and   said CVT selectively increasing and reducing the rotational speed thereof based on the relative movement of the input plates toward and away from each other.   
     
     
       16. The apparatus as set forth in claim 15, wherein the adjusting means includes: a hydraulic cylinder for moving one of the input plates in accordance with hydraulic pressure therein; and   an electromagnetic valve for controlling the hydraulic pressure in the hydraulic cylinder.   
     
     
       17. The apparatus as set forth in claim 16, wherein said control means computes an insufficient level of the maximum chargeable voltage with respect to the required torque, and wherein said control means controls the electromagnetic valve to reduce the rotational speed of the CVT based on the insufficient level. 
     
     
       18. A control apparatus for a vehicle including a power transmitting system between an engine and wheels, said transmitting system having a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode to reduce engine speed and an assisting operation mode to increase the engine speed, said apparatus comprising: recognizing means for recognizing a shift of the engine speed;   computing means for computing a total moment of inertia of the engine, the CVT and the motor-generator, for computing the torque of the engine, the CVT and the motor-generator based on each of the computed inertia moments and a difference between the engine speeds of the current cycle and the previous cycle, and for computing the total amount of torque;   actuating means for actuating the motor-generator in one of the operation modes in accordance with the recognized shift of the engine speed; and   correcting means for correcting the engine speed using at least one of said computed values.   
     
     
       19. The apparatus as set forth in claim 18, wherein said recognizing means includes an electric control unit (ECU) for setting a current flag when the ECU recognizes the shift of the engine speed and for resetting a previous flag. 
     
     
       20. The apparatus as set forth in claim 19, wherein said actuating means includes said electric control unit for actuating the motor-generator in the regenerating operation mode according to the flag indicative of an increase in the engine speed increase and in the assisting operation mode according to the flag indicative of a reduction of the engine speed. 
     
     
       21. The apparatus as set forth in claim 20, wherein said motor-generator is alternately actuated in the regenerating operation mode and the assisting operation mode to maintain a substantially average vehicle speed. 
     
     
       22. A control apparatus for a vehicle including a power transmitting system between an engine and wheels, said transmitting system having a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode to charge a power source and reduce the engine speed and an assisting operation mode to increase the engine speed, said apparatus comprising: hydraulic control means for controlling said CVT;   detecting means for detecting a temperature of fluid in the hydraulic control means being smaller than a predetermined magnitude, wherein said predetermined magnitude is a minimum level for ensuring a start-up pressure of the fluid;   determining means for determining an increase of the engine speed;   computing means for computing torque required to reduce the engine speed in association with a delay of the start-up pressure of the fluid; and   actuating means for actuating the motor-generator in the regenerating mode to charge the power source with voltage based on the required torque, wherein the CVT includes: an input shaft for receiving engine power;   a pair of input plates relatively movable away from and toward each other on the input shaft;   an output shaft;   a pair of output plates relatively movable away from and toward each other on the output shaft; and   a power transmitting belt for operably connecting the input plates and the output plates, wherein the rotational speed of the CVT is selectively increased and reduced based on the relative movement of the input plates toward and away from each other.     
     
     
       23. The apparatus as set forth in claim 22, wherein said computing means computes the required torque based on a difference between a start-up delay of the engine and a start-up delay of the CVT. 
     
     
       24. The apparatus as set forth in claim 23, wherein the adjusting means includes: a hydraulic cylinder for moving one of the input plates in accordance with hydraulic pressure therein; and   an electromagnetic valve for controlling the hydraulic pressure in the hydraulic cylinder.   
     
     
       25. A continuously variable transmission for an engine driven vehicle, comprising: an input shaft for receiving engine power;   a pair of input plates relatively movable away from and toward each other on the input shaft;   an output shaft;   a pair of output plates relatively movable away from and toward each other on the output shaft; and   a power transmitting belt for operably connecting the input plates and the output plates, wherein the rotational speed of the CVT is selectively increased and reduced based on the relative movement of the input plates toward and away from each other.